TOKYO >> Leaders from Japan and the Association of Southeast Asian Nations, marking their 50th anniversary of friendship, were meeting at a special summit on Sunday and expected to adopt a joint vision that emphasizes security cooperation amid growing tensions with China in regional seas.

Ties between Japan and ASEAN used to be largely based on Japanese assistance to the developing economies, in part due to lingering bitterness over Japan’s wartime actions. But in recent years the ties have focused more on security amid China’s growing assertiveness in the South China Sea, while Japan’s postwar pacifist stance and trust-building efforts have fostered friendlier relations.

“Based on our strong relationship of trust, it is our hope that Japan and ASEAN will bring together their strengths and find solutions in an era of compound crises that are difficult for any one country to solve,” Prime Minister Fumio Kishida said in a speech on Saturday night at the State Guest House in Tokyo.

“As we co-create and build upon stronger and more vibrant economies and societies, we will be better able to secure a free and open international order based on the rule of law,” he added.

Kishida proposed bolstering ties between Japan and ASEAN in security as well as in business, investment, climate, technology and people exchanges. Kishida and this year’s ASEAN chair, Indonesian President Joko Widodo, are set to announce a joint vision on Sunday after several sessions.

On Saturday, on the sidelines of the Dec. 16-18 summit, Kishida held a series of bilateral talks as Japan seeks to step up bilateral security ties with ASEAN countries.

Kishida and his Malaysian counterpart, Anwar Ibrahim, signed a 400 million yen ($2.8 million) deal to bolster Malaysia’s maritime security capability. It is a new Japanese official security assistance program specifically for militaries of friendly nations to help strengthen their law enforcement and security capabilities.

The assistance includes provisions of rescue boats and other equipment to help improve the military capability of Malaysia, which sits at a crucial location on sea lanes connecting the Indian Ocean and East Asia and serves a vital role in warning and surveillance operations for the entire region.

Separately on Saturday, Kishida signed a deal with Widodo, offering a grant of up to 9.05 billion yen ($63.7 million) to fund Indonesia’s maritime security capability advancement plan and includes a Japanese-built large-scale maritime patrol boat.

In November, Japan announced a provision of coastal surveillance radars to the Philippine navy, and the two sides also agreed to start talks for a key defense pact called the Reciprocal Access Agreement designed to smooth their troops’ entry into each other’s territory for joint military exercises.

Later that month, Japan and Vietnam agreed to elevate the status of their relationship to a top-level comprehensive strategic partnership, under which they will discuss details of a possible deal to broaden their defense cooperation.

But ASEAN countries are not in lockstep in their stance toward China, with which many have strong ties and are reluctant to choose sides. Japanese officials say they are mindful of the situation and not trying to get them to choose sides.

Japan also hopes to push forward energy cooperation with ASEAN leaders at a summit for the Asian Zero Emission Community initiative planned for Monday, when Australian Prime Minister Anthony Albanese is expected to join online.